Researchers at the University of California at Berkeley have built a high-speed camera that can capture actual brain signals as they occur.
…The new imaging technique combines two-photon fluorescence microscopy and all-optical laser scanning in a state-of-the-art microscope that can image a two-dimensional slice through the neocortex of the mouse brain up to 3,000 times per second. That’s fast enough to trace electrical signals flowing through brain circuits. (High-speed microscope captures fleeting brain signals)